摘要
目前尚未有划分陆相断陷盆地页岩岩相组合的研究成果和技术方法,不同页岩岩相组合的基本特征还需要进一步明确.在页岩油井取心井段岩心精细观察描述的基础上,利用岩石薄片观察和X射线-全岩矿物衍射分析明确取心段页岩的基本岩石和岩相类型,通过主要矿物成分及主微量元素测试分析,提取济阳坳陷古近系页岩沉积古环境信息;依据四古环境(古气候、古物源、古盐度、古水深)基本特征,按照沉积环境相似性以及内部结构均一性等原则对东营凹陷沙四上亚段页岩层系进行岩相组合划分,建立了基于沉积环境主控的页岩岩相组合分级划分方案,并结合储层和有机地化分析测试明确了主要岩相组合的储集性和含油性特征.结果表明:(1)东营凹陷沙四上页岩是典型的富碳酸盐页岩(碳酸盐质页岩)和混积型页岩,纹层特征显著,孔隙类型多样,层理缝和构造缝较发育,有机质丰度高,演化程度中等-低,埋藏深、压力系数高.(2)依据沉积构造部位、古环境,东营凹陷沙四上亚段页岩可划分为8类岩相组合,在盆地中心以发育基质型碳酸盐质页岩岩相组合为主、块状白云岩夹层型页岩岩相组合为辅,在北部陡斜坡带主要发育砂岩夹层型页岩岩相组合,在南部缓斜坡带主要发育块状白云岩夹层型以及纹层状灰质泥岩和白云岩互层等页岩岩相组合.(3)一般地,作为细粒沉积的主体,东营凹陷洼陷中心沙四上亚段基质型页岩层系自底至顶依次发育纹层状泥质灰岩夹块状白云岩相、纹层状泥质灰岩和白云岩互层相、纹层状泥质灰岩和灰质泥岩互层相、纹层状泥质灰岩夹灰质泥岩相、层状泥质灰岩和灰质泥岩互层相、层状泥质灰夹灰质泥岩相等,揭示沉积古环境由干旱、咸水、半深水、少物源向半湿润、半咸水、深水、较多物源的变化.(4)纹层状泥质灰岩夹灰质泥岩组合以及纹层
There are no relevant research results and technical methods on the classification of shale lithofacies combinations in continental faulted basins,and the basic characteristics of different shale lithofacies assemblages need to be further clarified.Based on the fine observation and description of the core samples,the basic rock and lithofacies types of the sampled shale sections were identified by observing rock thin sections and performing X-ray-based full-rock mineral diffraction analysis.By analyzing the major mineral composition and major and trace element contents of the samples,information about the sedimentary paleoenvironment of the Jiyang Depression was extracted.According to the basic characteristics of the four paleoenvironment factors(paleoclimate,paleosource,paleosalinity,paleowater depth),the shale stratigraphy of the Upper Sub-member of the Fourth Member of Shahejie Formation(Es4s)in the Dongying Sag was divided into lithofacies combinations based on the principle of sedimentary environment similarity and internal structure uniformity.A lithofacies combination classification scheme based on sedimentary environment control was established,and combined with reservoir and organic geochemical analysis,the main lithofacies combination reservoir and oil-bearing characteristics were clarified.Results show that:(1)Es4s shale in the Dongying Sag is a typical carbonate-rich shale(carbonate shale)and mixed shale,with significant lamination features,various types of pores,well-developed bedding and structural fractures,high organic matter abundance,moderate-to-low evolutionary degree,deep burial depth and high pressure coefficient.(2)Based on sedimentary structural position and paleoenvironment,the Es4s shale in the Dongying Sag can be divided into 8 lithofacies combinations.In the central part of the basin,the matrix carbonate shale lithofacies combination is dominant,with some interbedded block dolomite shale lithofacies combination.In the northern steep slope belt,the sandstone interbedded shale lithofacies
作者
刘惠民
张顺
王学军
张鹏飞
李军亮
王勇
魏晓亮
银燕
朱德燕
Liu Huimin;Zhang Shun;Wang Xuejun;Zhang Pengfei;Li Junliang;Wang Yong;Wei Xiaoliang;Yin Yan;Zhu Deyan(Shengli Oilfield Company,SINOPEC,Dongying 257000,China;Research Institute of Petroleum Exploration and Development,Shengli Oilfield Company,SINOPEC,Dongying 257015,China;Working Stations for Postdoctors of Shengli Oilfield,SINOPEC,Dongying 257015,China)
出处
《地球科学》
EI
CAS
CSCD
北大核心
2023年第1期30-48,共19页
Earth Science
基金
国家重点基础研究发展计划(973计划)项目(No.2014CB239100)
国家专项(No.2017ZX05049)
国家自然科学基金项目(No.4217020748)。
关键词
页岩岩相组合
沉积环境
储集空间
含油性
断陷盆地
东营凹陷
石油地质学
shale
lithofacies combination
sedimentary environment
reservoir space
oil-bearing
faulted basin
Dongying Sag
petroleum geology
